In the display technique field, along with the increased requirements on such display performance as the size enlargement of display devices and the improvement of refresh rate, the requirement on the resistance of the structures such as gate lines and data lines in metal layers is also increased accordingly. Currently, due to high resistivity, aluminum wires which are mainly used at present can not meet the requirements of display performance. While the resistivity of copper is 30% lower than the resistivity of aluminum, therefore, it becomes a common selection that the structures such as gate lines and data lines in metal layers are made from copper.
In liquid crystal display devices, for instance, in a liquid crystal display device of ADS (Advanced Super Dimension Switch) mode, parasitic capacitance is generated between a common electrode and a metal layer (for example, a gate metal layer or a source/drain layer) which are disposed on an array substrate. This results in an excessive power consumption of the display device. Forming of a thick organic insulating layer (for example, a resin layer) between the common electrode and the metal layer can reduce the capacitance of the circuits, thus, the power consumption is reduced. This configuration has been widely applied to products so far.
The combination of a copper metal layer and an organic insulating layer can be applied to reduce the resistance and the capacitance, thus significantly reducing impedance and power consumption and improving the performance of a product.